The invention relates to a glue gun for conducting adhesive bonding by means of heated adhesive. The gun comprises a heating section and an angled handle with a hollow metal block which accommodates adhesive being arranged in the heating section.
Glue guns are known from practical usage comprising an elongated hollow block with a cylindrical recess, the hollow block consisting of a thermally conductive material, preferably a metal such as aluminum. An electrical heating element is in close contact with the hollow block and is used for heating the hollow block and, by way of the latter, an adhesive cartridge inserted in the block. The adhesive, softened by the heating step, can be readily extruded mechanically by means of a piston from the front end of the glue gun. One disadvantage in such glue guns resides in that they are heated by means of electric current, and an external source of current is required, on the one hand, due to the power required for heating and softening the adhesive and, on the other hand, in view of a long, continuous usefulness of such a gun, inasmuch as batteries could not generate the necessary energy.
Therefore, the invention is based on the object of creating a glue gun usable independently of an external source of current which yet is adequately powerful and also can be utilized in a continuous fashion for a sufficiently long period of the time.
According to the invention, the aforementioned object is attained by a glue gun comprising a hollow combustion chamber equipped with air inlet openings and provided integrally with a metal block of the gun which accommodated adhesive. A fuel tank is arranged in the handle; and that a connecting conduit is extended from the tank to the combustion chamber. A shutoff element is located in the connecting conduit. In a preferred embodiment of the glue gun, the combustion chamber is arranged at least partially annularly around the block.
Liquid gas is employed as the carrier for heating energy. The gas is contained in the fuel tank which can be either exchangeable or refillable. A high and adequate heating power is obtained by the use of liquid gas, which power can be used continuously for a long time without the necessity of interruption. Therefore, the glue gun of this invention can be utilized at various sites, especially where no electrical current supply is available. By the preferred construction of a combustion chamber arranged coaxially to the block, which latter contains the adhesive, or an annular combustion chamber, a heat generation is ensured that is equally distributed along the periphery. In order to heat the adhesive likewise in an optimally uniform fashion over a relatively long stretch, another preferred embodiment provides that the connecting conduit is extended in a spiral shape within the combustion chamber and the section of this conduit arranged within the combustion chamber is provided with outlets distributed over the length of this section. Thereby, the combustion process is allowed to proceed practically over the entire length of the combustion chamber, making it possible to effect a uniform operation by means of the glue gun of this invention.
In order to improve the combustion process, the provision is made that a combustion catalyst is fashioned as a double-cylinder shell, or that the conduit section in the combustion chamber is produced, as a combustion catalyst, of a wire mesh.
Additional advantages and features of the invention can be seen from the following description explaining embodiments of the glue gun of this invention in detail.